In a tape cassette used with a recording and/or reproducing device, such as VTR, equipped with rotative magnetic heads, a portion of the magnetic tape is brought to the outer front side of the cassette proper, in order that the magnetic tape may be automatically extracted by tape extracting means of the recording and/or reproducing device and placed about the rotative magnetic head by loading means of the recording and/or reproducing device. On the front side of the cassette proper, there is provided a recessed area into which the tape extracting unit is to be introduced for extracting the magnetic tape, that is, a treading area. On the front side of the cassette proper, there is further provided a lid or cover for overlying and protecting the portion of the tape facing to the outer front side of the cassette proper. Such lid or cover of the conventional tape cassette has angularly arranged side sections pivotally supported by the side wall sections of the cassette proper so that the lid may be partially rotated for opening or closing the front side of the tape cassette.
There is also known a recording and/or reproducing device filed in the name of the present Applicant, wherein tape cassettes with different tape lengths are provided in different sizes depending on such different tape lengths can be used for recording and/or reproduction by the same device. Despite the difference in the cassette size, the tape cassettes used with this type of the recording and/or reproducing device are provided with the threading area of the same design in order that the magnetic tape may be extrated using the same tape extraction unit, thereby assuring interchangeability between the different size cassettes. Since the magnetic tape can be extracted by the tape extraction unit provided that the tape is brought to said threading area, the tape is caused to face outside at the standardized threading area no matter whether the larger or lesser size cassettes are in use.
In these tape cassettes of different sizes, when the lid for opening or closing the threading area at the front side of the tape cassette is journaled at the side wall sections of the cassette proper, as in the aforementioned prior-art devices, the lid as a whole tends to be bulky in size in the case of the large size tape cassette despite the fact that the threading area is of the same design as the small size tape cassette. This is inconvenient since the lid is caused to overlie the portion of the front side of the cassette proper lying outside of the threading area along which the tape is extended and which should be in need of protection. Also the lid may be insufficient in mechanical strength.
In view of the foregoing disadvantages of the prior art tape cassette, it is an object of the present invention to provide an improved tape cassette having a novel system for mounting the lid to the cassette proper.
It is another object of the present invention to provide an improved tape cassette in which the side sections of the lid supporting the shafts about which the lid is rotated for opening or closing the threading area on the front side of the cassette are pivotally mounted at the mounting positions inwardly offset from both sides of the cassette proper. In this manner, the length of the main portion of the lid need only be sufficient to cover the threading area, so that the lid as a whole may be reduced in size and weight.
It is a further object of the present invention to provide an improved tape cassette wherein the side sections of the lid are rotatably supported at the mounting positions inwardly offset from both ends of the cassette proper whereby movable sections are not provided at the four corners of the cassette so as to elevate the strength of the cassette proper.
It is a further object of the present invention to provide an improved tape cassette wherein positive tape protection is assured by obviating the risk of inadvertent opening of the lid upon mannual handling of the tape cassette.
It is a further object of the present invention to provide an improved tape cassette wherein the lid damage caused by dropping the tape cassette may be avoided.